Enabling -fstack-protector-strong in makepkg.conf?

A little more than a year ago Google submitted a patch which added a -fstack-protector-strong option which was intended to strike a balance between -fstack-protector (used in Arch) and -fstack-protector-all which was considered too computationally expensive for google's chromiumos. All of these options introduce measures to protect compiled programs against stack overflow attacks to varying degrees of security and performance.

My recently installed default /etc/makepkg.conf shows -fstack-protector (not -strong) in CFLAGS. Is there a specific reason that it has not yet been implemented in Arch, or has it simply just "not happened" yet?

Fedora 20 is now using -fstack-protector-strong. After some searching I couldn't find anything here or on the arch bugtracker which discusses the new option. I should add that I am by no means well-versed in security and this is something I would like to know more about.